M333Cb Whitefish/Swan Mountains

Landscape Characteristics:

Block faulted mountains that formed from argillite, siltite, and dolomite and strongly shaped by alpine glaciation. Glacial till covers much of the landscape. Some volcanic ash deposits also occur. Elevations range from 2900 to 8000 feet. Drainage density is moderate. Lakes occur in glacial cirques and in glacial valleys.

Climate:

Mean annual precipitation ranges from 20 to 110 inches, about 80 percent falling as snow. The soil temperature and moisture regimes are cryic and udic.

Potential Vegetation:

Douglas-fir forest and Western spruce-fir forest

Relationships of Dominant Map Unit Components:

Landform Geology Soil Taxa
Mountainsides Till/volcanic ash Cryoboralfs/Eutroboralfs
Alpine ridges/cirquelands Argillite/dolomite/till Cryochrepts
Valley floors Alluvium/outwash Eutrochrepts/Udifluvents/Cryoboralfs

Disturbance and Land Use:

The primary natural disturbances are fire, insects, and windthrow. Land use is predominantly rural and suburban development. Some timber harvest also occurs.